Optional parameters and named parameters in C# 4.0

Feb 9, 2010 Posted by Lara Kannan
Optional parameters and named parameters in C# 4.0

Imagine you have two List. Two new features to C# 4.0 are optional parameters and named parameters.

Optional parameters have been a part of VB.Net but it's now possible to do this in C#. Instead of using overload methods, you can do this in C#:

private string SomeMethod(string givenName,
string surname = "Kannan",
int age = 10)
{
return givenName + " " + surname;
}

The second and third parameters, surname & age, both have default values. The only parameter required is givenName. To call this method you can either write this:

string name = null;
name = SomeMethod("Arjun");

That will return Arjun Kannan. You can also do this:

string name = null;
name = SomeMethod("FName", "LName");

The value returned is FName LName. But what if you didn't want to specify a surname but you did want to pass the age? You can do this by using named parameters:

string name = null;
name = SomeMethod("Rangoli", age: 20);

These are nice additions to the language.

Share
Labels: , ,

Post a Comment